For patients who have to permanently monitor the concentration of a specific analyte in the body and provide to the body medicaments for adapting this analyte to physiological values, a considerable effort arises.
So, for example patients with diabetes have to measure multiple times a day the blood glucose which is used as a basis for a therapy decision. In doing so, the skin is perforated for example with a lancet and the thereby emerging blood is applied on a measuring strip as part of a measuring system. After availability of the measurement value the insulin dose is calculated wherein the insulin is injected into the fat tissue by means of a needle. This measurement/injection cycle is associated with two skin penetrations causing pain. Further, the insulin is administered in a “non-physiological” dosage. For optimizing the uniform dosage, insulin pumps have been developed which continuously deliver the insulin through an implantable catheter. Besides the advantage of the continuous delivery of the insulin, the pump catheter may reside in the tissue for a longer time, whereby a multiple piercing is omitted and the inconveniences associated therewith can be avoided.
From AT 408.182 B there is known a glucose sensor in which by means of a setting needle a catheter is brought into the tissue of a living organism. After the positioning of the catheter in the tissue the setting needle is retracted and replaced by a tube-like carrier with an electrochemical sensor. The sensor is located at the outer periphery of the tube-like carrier in the region of a wall opening of the catheter inserted into the tissue such that a measurement contact to the surrounding tissue can be established. The electrical supply line of the sensor is conducted in an annular gap between the tube-like carrier and the catheter outwardly to an evaluation unit. The inside lumen of the tube-like carrier as well as the annular channel between the tube-like carrier and the catheter is respectively connected with a syringe pump by means of which liquids can be brought into the tissue. Therefore in an insulin administration with this device, for measurement and application only one skin penetration is necessary.
From WO 96/36275 there is known a method and a device for transcutaneous measurement of an analyte in living tissue, in which a fluorescence indicator immobilized in a carrier tissue is implanted in the tissue. As carrier is used a planar or cylindrical membrane, for example a cellulose membrane permeable for glucose. The membrane comprises a tissue compatible fluorescence indicator which reacts on a change in the glucose concentration with a change in its fluorescence decay time or with a frequency shift. The excitation radiation is irradiated through the tissue from an outside located light source and the emerging measurement radiation gets through the tissue and the skin to an outside located detector the signals of which are supplied to an evaluation and display device. The administration of a medicament however is, due to the implanted sensor device, neither intended nor possible such that for example for an insulin administration an additional skin penetration would be necessary.
Further, a series of applications is known (see e.g. US 2009/0088615 A1), in which in vivo glucose measurements are carried out with a light guide insertable into the tissue, wherein different applications are described by means of which the measurement radiation can be separated from the excitation radiation.
Further, from WO 2006/102412 A2 a device is known which comprises an insulin pump and an apparatus for glucose measurement. Implementation variants are described in which, on an infusion canula for a medicament, electrochemical measurement apparatuses consisting of reference electrodes and counter electrodes are attached for measuring, after insertion of the canula into the tissue, an analyte concentration. According to a further implementation variant an electrochemical sensor with several electrodes is implemented as small as possible and is wound around the outer periphery of the catheter insertable into the tissue. All these implementation variants are technically very laborious, increase the diameter of the tissue canula and impair the quality of the surface of the canula, thereby hindering insertion into the tissue.